There is an abandoned proposal https://wiki.openstreetmap.org/wiki/Proposed_features/Ditch titled "Drainage/Irrigation Ditch"
and the German page https://wiki.openstreetmap.org/wiki/DE:Tag:waterway=ditch mentions "Bewässerungsgraben" which means irrigation ditch. _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
